The document is a product brochure for TVR-Line voltage regulators manufactured by Zhejiang Farady Electric Co., Ltd. It summarizes the company profile and provides details on the voltage regulators' applications, working principles, technical specifications, structure, functions, installation examples, and answers to frequently asked questions. The voltage regulators can automatically adjust output voltage to keep it stable within ±10-30% of the rated voltage and improve power quality and supply reliability for distribution lines.